Fix typos in README.
Fix typos in README.

MishaMykhalyuk/rivets,mikeric/rivets,QAPInt/rivets,benderTheCrime/tiny-rivets,mikeric/rivets,MishaMykhalyuk/rivets,npmcomponent/mikeric-rivets,jccazeaux/rivets,MishaMykhalyuk/rivets,moneyadviceservice/rivets,QAPInt/rivets,GerHobbelt/rivets,re-clone/rivets,mikeric/rivets,re-clone/rivets,altmind/rivets,nopnop/rivets,zongkelong/rivets,QAPInt/rivets,jccazeaux/rivets,nopnop/rivets,altmind/rivets,jccazeaux/rivets,re-clone/rivets,GerHobbelt/rivets,GerHobbelt/rivets,zongkelong/rivets,nopnop/rivets,kangax/rivets,altmind/rivets,zongkelong/rivets